Watson stuns Cibulkova in Montreal

Heather Watson recorded on of the biggest upsets of the Rogers Cup so far when she beat 10th seed Dominika Cibulkova 6-2 6-7(3) 7-6(5) on Wednesday.

The British No.1 made a mockery of the 45-place gap in the WTA rankings to topple the Slovakian, who reached the final of the Australian Open in January.

Watson got off to a fast start, breaking the world No.12 twice before allowing Cibulkova back into the match in a second set which saw both players drop serve on two occasions.

Qualifier Watson let a 5-2 lead slip away in the third set before rallying to take one of her biggest scalps. The 22-year-old will next face No.11 Victoria Azarenka in the third round on Thursday.

Watson, who needed to get through two qualifying matches to reach the main draw in Toronto, has never beaten former world No.1 and two-time grand slam champion Azarenka - winning just four games in three straight-set defeats.

World No.1 Serena Williams dispatched Samantha Stosur 6-0 6-2 in a match interrupted for 28 minutes by a sprinkle of rain.

Williams needed only 59 minutes to beat Stosur and set up a match against Lucie Safarova, a 6-4 6-2 winner against Magdalena Rybarikova. Williams is 6-0 against Safarova.

"She is an interesting player," Williams said. "She's extremely tricky. We've had some tough matches. I know we've gone to three sets on occasions. It's definitely not an easy match for me."

Williams has won the Rogers Cup three times when it is held on alternate years in Toronto, including last year, but she has not played in Montreal since she retired from the final with an injury in 2000.

"I'm really happy to be a part of the tournament this year. It's just really cool," she said. "I've actually been studying French for most of my life, so yeah, I should be able to speak even better, to be honest. I love it in Canada because I understand everything. It's a lot easier for me to speak. The accent is much easier for me to understand."

Maria Sharapova survived a rough first set to down Garbine Muguruza 4-6 6-3 6-1.

"I was happy that I was able to turn it around," Sharapova said. "I didn't feel good. I made a lot of errors in the first set. When you're able to finish stronger than your start, that's always a positive because you give yourself an opportunity to keep playing in the tournament."